干密度及初始含水率对含细粒土砾红层重塑土渗透性的影响

Influence of Dry Density and Initial Water Content on Permeability of Fine Gravelly Red-bed Remoulded Soil

了解含细粒土砾红层边坡在不同雨强条件下干密度及初始含水率对渗透性的影响将有助于边坡稳定性分析。为此,特剔除含细粒土砾中粒径大于2 mm以上的颗粒,制备了不同干密度及初始含水率的5组重塑土试样并做了变水头渗透试验。试验结果表明,渗透速度—水力坡降曲线、渗透系数—水力坡降曲线具有明显的三段线特征,干密度对第一、二转折点水力坡降的影响大于初始含水率;同一干密度条件下,初始含水率对渗透速度—水力坡降曲线中第二段曲线斜率k影响最大;同一初始含水率条件下,干密度对第一段曲线斜率a、第三段曲线斜率b影响最大。

In order to study the influence of dry density and initial, water content on the permeability of red-bed slope consisted of fine gravelly soil under different rainfall intensity, the variable head permeability test was conducted to fine gravelly remolded soil samples but exclude more than 2 mm grain size particles. And the samples were grouped in five by initial moisture contents or dry densities. Test results show that the permeability velocity-hydraulic gradient curves and permeability coefficient-hydraulic gradient curves can be divided into three segments. Moreover dry density has greater impact on the first and second turning point of hydraulic gradient values than that of initial moisture contents. Under the same dry density condition, initial moisture contents are more important to k values which stood for the second segment of permeability velocity hydraulic gradient curve＇s slope; when the initial moisture contents are the same, dry density will be more important to slope a and slope b values which stood for the first and the second segment of permeability velocity- hydraulic gradient curve＇ s slope, respectively.